4519-46-4Relevant articles and documents
Α, α-difluoropropionic production of esters
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Paragraph 0140-0142, (2016/10/10)
PROBLEM TO BE SOLVED: To provide a practical method of producing α,α-difluoro esters important as pharmaceutical and agricultural chemical intermediates. SOLUTION: The α,α-difluoro esters are produced by reacting α-halogeno-α-fluoro esters with salts or complexes comprising an organic base and hydrogen fluoride. Dehydrohalogenation of side reaction is controlled in the production method. Only α-fluoro-α,β-unsaturated esters of by-products are treated to be brought specifically into a high boiling-point, a boiling point difference gets remarkably large thereby between the α,α-difluoro ester of an objective product and the unsaturated ester of by-product, and a high purity product of the objective product is efficiently obtained by fractional distillation of a simple operation. The method is the practical method of producing the α,α-difluoro esters capable of solving a problem point in a prior technique. COPYRIGHT: (C)2012,JPOandINPIT
ISOMERIZATION OF 5-ACYL-6-HALO-1,6-DIAZABICYCLOHEXANES, A CASE OF INVERSION RATHER THAN 1,2-ACYL MIGRATION
Shustov, G. V.,Denisenko, S. N.,Chervin, I. I.,Zolotoi, A. B.,D'yachenko, O. A.,et all
, p. 1076 - 1079 (2007/10/02)
X-ray diffraction structural analysis and 13 C and 15 N NMR spectroscopy were used to establish that the final product of the halogenation of 5-acyl-1,6-diazabicyclohexane is the oxo-6-halo derivative.Thus, the observed transformation of the initially formed endo-N-chloro isomer is an inversion and not 1,2-acyl migration as previously proposed.
